Analysis & Opinion

ISTANBUL (Reuters) - Bodies are still being discovered after an alleged chemical weapons attack on the outskirts of Damascus that killed hundreds of people and the death toll will rise, a Syrian opposition spokesman said on Thursday.

The opposition accused government forces of gassing hundreds of people on Wednesday by firing rockets that released deadly fumes over rebel-held Damascus suburbs, killing men, women and children as they slept.

"We expect the number (of dead) to grow because we just discovered a neighborhood in Zamalka where there are houses full of dead people," Syrian National Coalition spokesman Khaled Saleh told Reuters in Istanbul, where the opposition has held regular meetings throughout the conflict.

Estimates for the death toll have ranged from 500 to well over double that number, which would make it the world's most lethal chemical weapons attack since the 1980s. Syrian authorities have denied government forces used chemical weapons.

Fahad Almasri, spokesman for the rebel Free Syria Army in Paris, said its branch in Damascus had documented 1,729 deaths following Wednesday's attack. He added that 6,000 people were also suffering from breathing problems.

The opposition has demanded that U.N. chemical weapons inspectors immediately investigate the besieged rebel-held area outside the capital. France said the world should respond with force if the chemical allegations prove true.

"There is a time limit for when the inspectors can prove with high probability that chemical weapons were used. We are saying let the inspectors go in either today, or tomorrow at the most," Saleh said.

The alleged attack prompted an emergency meeting of the U.N. Security Council in New York. It did not explicitly demand a U.N. investigation, although it said "clarity" was needed and welcomed U.N. Secretary General Ban Ki-moon's calls for a prompt investigation by the inspection team in Syria.

Saleh said that international inaction after alleged chemical weapons attacks by Syrian government forces earlier in the conflict had emboldened President Bashar al-Assad.

"Politics is knocking on closed doors and we understand that the U.N. is one of those closed doors for us," he said. "We will continue pursuing a political solution but at the same time that does not stop us from pursuing other alternatives."